input.c

   1 /*
   2
   3     PROGRAM_NAME PROGRAM_VERSION - PROGRAM_DESCRIPTION
   4
   5     Copyright (C) 2003 Angel Ortega <angel@triptico.com>
   6
   7     This program is free software; you can redistribute it and/or
   8     modify it under the terms of the GNU General Public License
   9     as published by the Free Software Foundation; either version 2
  10     of the License, or (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20
  21     http://www.triptico.com
  22
  23 */
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27
  28 #include "input.h"
  29
  30 /*******************
  31         Data
  32 ********************/
  33
  34 extern int _frequency;
  35
  36
  37 /*******************
  38         Code
  39 ********************/
  40
  41 int fget16(FILE * f)
  42 {
  43         int c;
  44
  45         c=fgetc(f);
  46         c+=(fgetc(f) * 256);
  47
  48         return(c);
  49 }
  50
  51
  52 int fget32(FILE * f)
  53 {
  54         int c;
  55
  56         c=fgetc(f);
  57         c+=(fgetc(f) * 256);
  58         c+=(fgetc(f) * 65536);
  59         c+=(fgetc(f) * 16777216);
  60
  61         return(c);
  62 }
  63
  64
  65 int load_sample(FILE * f, int bits)
  66 {
  67         short int s;
  68
  69         if(bits==8)
  70         {
  71                 s=fgetc(f)-128;
  72                 s<<=8;
  73         }
  74         else
  75         {
  76 /*              s=fgetc(f);
  77                 s|=(((unsigned char)fgetc(f)) << 8);*/
  78                 s=fget16(f);
  79         }
  80
  81         return(s);
  82 }
  83
  84
  85 void load_pcm_wave(FILE * f, int * size, int bits, int channels,
  86         int frequency, int ** lwave, int ** rwave)
  87 {
  88         int n;
  89         int * ls;
  90         int * rs;
  91
  92         ls=(int *)malloc(*size * sizeof(int));
  93
  94         if(channels==2)
  95                 rs=(int *)malloc(*size * sizeof(int));
  96         else
  97                 rs=ls;
  98
  99         for(n=0;n < *size;n++)
 100         {
 101                 ls[n]=load_sample(f, bits);
 102
 103                 if(channels==2)
 104                         rs[n]=load_sample(f, bits);
 105         }
 106
 107         /* resample if needed */
 108         if(frequency != _frequency)
 109         {
 110                 ls=wave_resample(ls, frequency, size);
 111
 112                 if(channels==2)
 113                         rs=wave_resample(rs, frequency, size);
 114                 else
 115                         rs=ls;
 116         }
 117
 118         *lwave=ls;
 119         *rwave=rs;
 120 }
 121
 122
 123 int * wave_resample(int * wave, int freq, int * size)
 124 {
 125         double ratio;
 126         int new_size;
 127         int * new_wave;
 128         int n;
 129         double i;
 130
 131         ratio=(double) freq / (double) _frequency;
 132         new_size=(int)((double) (*size) / ratio);
 133
 134         new_wave=(int *)malloc(new_size * sizeof(int));
 135
 136         printf("wave_resample: ratio %f\n", (float)ratio);
 137
 138         for(n=i=0;n < new_size;n++,i+=ratio)
 139                 new_wave[n]=wave[(int)i];
 140
 141         *size=new_size;
 142
 143         /* free the old wave */
 144         free(wave);
 145
 146         return(new_wave);
 147 }
 148
 149
 150 int load_wav_file(char * filename, int * size, int ** lwave, int ** rwave)
 151 {
 152         FILE * f;
 153         char dummydata[256];
 154         int rlen,flen;
 155         short int b_per_sec,num_channels,tag;
 156         char riffid[5],waveid[5],fmtid[5],dataid[5];
 157         int wav_frequency, wav_bits;
 158         int * ls;
 159         int * rs;
 160
 161         if((f=fopen(filename,"r"))==NULL)
 162                 return(0);
 163
 164         fread(riffid,1,4,f);
 165         riffid[4] = 0;
 166         fread(&rlen,1,4,f);
 167         fread(waveid,1,4,f);
 168         waveid[4] = 0;
 169
 170         if(strcmp(waveid,"WAVE"))
 171         {
 172                 fclose(f);
 173                 return(0);
 174         }
 175
 176         fread(fmtid,1,4,f);
 177         fmtid[4] = 0;
 178         flen=fget32(f);
 179
 180         if(flen>240)
 181                 flen=240;
 182
 183         fread(&tag,1,2,f);
 184
 185         num_channels=fget16(f);
 186         wav_frequency=fget32(f);
 187         b_per_sec=fget32(f);
 188
 189         wav_bits=fget16(f) / num_channels;
 190         wav_bits*=8;
 191
 192         fread(dummydata,1,(size_t)flen-14,f);
 193         fread(dataid,1,4,f);
 194         dataid[4] = 0;
 195
 196         *size=fget32(f);
 197         if(wav_bits==16) (*size)/=2;
 198         if(num_channels==2) (*size)/=2;
 199
 200         load_pcm_wave(f, size, wav_bits, num_channels,
 201                 wav_frequency, &ls, &rs);
 202
 203         fclose(f);
 204
 205         *lwave=ls;
 206         *rwave=rs;
 207
 208         return(1);
 209 }
 210
 211